fix problem of persistable var saving in QAT (#47203)

python/paddle/fluid/contrib/slim/quantization/imperative/qat.py

@@ -32,6 +32,7 @@ from paddle.fluid.io import load_inference_model, save_inference_model
 from ..quantization_pass import ReplaceFakeQuantDequantPass, QuantWeightPass
 from paddle.fluid.log_helper import get_logger
 from .. import quantization_pass
+from ..utils import move_persistable_var_to_global_block
 from . import utils
 from . import fuse_utils
 
@@ -550,6 +551,8 @@ class ImperativeQuantizeOutputs(object):
 
             clip_extra = True
 
+        move_persistable_var_to_global_block(infer_program)
+
         save_inference_model(dirname=dirname,
                              feeded_var_names=feed_target_names,
                              target_vars=fetch_targets,

python/paddle/fluid/contrib/slim/quantization/post_training_quantization.py

@@ -449,21 +449,7 @@ class PostTrainingQuantization(object):
             self._collect_dynamic_quantize_op_threshold(
                 self._dynamic_quantize_op_type)
 
-        # Move sub blocks persistable var to global block
-        global_block = self._program.global_block()
-        for _op in global_block.ops:
-            if _op.type == "while":
-                _block_id = _op.attr("sub_block").id
-                _block = self._program.block(_block_id)
-                persistables = []
-                for _name, _var in _block.vars.items():
-                    if _var.persistable:
-                        global_block._clone_variable(_var)
-                        persistables.append(_name)
-                for _name in persistables:
-                    _block._remove_var(_name)
-                persistables.extend(_op.input('X'))
-                _op.desc.set_input("X", persistables)
+        utils.move_persistable_var_to_global_block(self._program)
 
         if not self._return_graph:
             return self._program

python/paddle/fluid/contrib/slim/quantization/utils.py

@@ -433,6 +433,24 @@ def calculate_quant_cos_error(orig_tensor, qdq_tensor):
     return cos_sim
 
 
+def move_persistable_var_to_global_block(program):
+    # Move sub blocks persistable var to global block
+    global_block = program.global_block()
+    for _op in global_block.ops:
+        if _op.type == "while":
+            _block_id = _op.attr("sub_block").id
+            _block = program.block(_block_id)
+            persistables = []
+            for _name, _var in _block.vars.items():
+                if _var.persistable:
+                    global_block._clone_variable(_var)
+                    persistables.append(_name)
+            for _name in persistables:
+                _block._remove_var(_name)
+            persistables.extend(_op.input('X'))
+            _op.desc.set_input("X", persistables)
+
+
 def l2_loss(gt, pred):
     return ((gt - pred)**2).mean()